The correct answer is (c) both
Work Step by Step
The correct answer is (c) both We could use conservation of energy to find the speed of the first ball when it swings down to the bottom. The collision removes energy from the system, so we need to use conservation of momentum to find the speed of both balls just after the collision. Then we can use conservation of energy to find the maximum height reached by both balls together. This will allow us to determine the angle.